Immense losses are incurred worldwide through the unauthorized use of computer programs. In order to counter these, solutions are developed for protecting computer programs against unauthorized access.
A transmission of encoded information for activating a computer program serves to prevent unauthorized reproductions of the computer program being made. Corresponding methods serve, for example, also as a technical prerequisite for marketing computer programs as products via e-commerce. In previously known methods for activating computer programs, computer programs are released with the aid of a respective registration key. In order to release a computer program, the registration key, which is permanently assigned to a computer program license, is input manually or imported from a data carrier. Particularly where there is a plethora of computer programs installed on different computers, this results in a high administrative outlay which is associated with personnel-intensive operating and maintenance work.
From EP 1 191 419 A2 a method is known in which predeterminable functions of a computer program can be released for a selectable period of use through modification of a registration key pair. The registration key pair has at least one piece of partial information blocked against user access. The functions to be released do not necessarily have already to have been available for release when the computer program was initially installed but can also be selected for addition subsequently. For the release, no deployment of operating or maintenance personnel is required at the location of the computer on which the respective computer program is installed.
Components of the registration key pair according to the method described in EP 1 191 419 A2 are application information and an application value. The application information is input on a first computer on which the computer program to be registered is installed, or is generated by said first computer. The application value is computed in a second computer from the application information by means of coding.
When a computer program is registered or when the registration is changed, first pieces of application information comprising at least one piece of partial information that is blocked against user access are transmitted to the second computer. In the second computer, an application value is computed from the first pieces of application information, said application value subsequently being transmitted to the first computer. By means of decoding, second pieces of application information are determined in the first computer from the application value. When execution of the computer program begins, the first and the second pieces of application information are checked as to whether they match. Depending on the deviations that arise in the checking, predeterminable functions of the computer program are released.